(CNN) -- Rory McIlroy enjoyed a triumphant march Sunday to his first major title as a two-under-par 69 gave him an eight-shot victory in the U.S. Open at Congressional Country Club in Maryland.

McIlroy's 16-under aggregate of 268 was a record for the U.S. Open, breaking the mark set by Tiger Woods, who was 12-under in winning at Pebble Beach in 2000.

He became only the third player in U.S. Open history to return all four rounds in the 60s and he was the youngest winner of the tournament since the legendary Bobby Jones in 1923.

"The whole week has been incredible," McIlroy said as he lifted the trophy.

"I know how good Tiger was at Pebble in 2000 and I went out today to try and emulate him in some way. Augusta was a valuable experience. I knew what I needed to do today to win. I put a few new things into practice and it paid off,"

Australian Jason Day closed with a three-under 68 to claim his second straight runner-up spot in a major on eight-under 276, but he never challenged runaway winner McIlroy.

The 22-year-old from Northern Ireland led from start to finish and took an eight-shot advantage into the final round over playing partner YE Yang, the 2009 PGA champion.

McIlroy's victory leaves all four holders of the major titles, South African Louis Oosthuizen who won last year's British Open, Germany's Martin Kaymer, the 2010 PGA champion and South African Charl Schwartzel, who took this year's Masters, under 30 years of age.

McIlroy doubtless settled his own nerves and those of his supporters, who feared a repeat of the disastrous rounds which ended his hopes at last year's British Open and April's Augusta Masters, with a first-hole birdie.

A spectacular approach to the fourth set up a second and extended his lead to double figures on 16-under-par.

His chasers would have been further frustrated by a 15-foot par save on the next and he reached the turn in two-under 34.

But he reserved his very best for the 218-yard 10th, positioned in front of the clubhouse where a huge gallery had gathered.

Yang played first and his approach finished within four feet of the hole. McIlroy with a six-iron bettered that as it rolled to within a few inches of the cup.

"Rory, Rory" was the chant from the crowd as if he was their own and he duly holed out for a birdie.

A dropped shot on the 12th scarcely interrupted his victory procession and he returned to 17-under with a birdie on the par-five 16th.

A three-putt bogey on the 17th was followed by a par on the last, holing a short putt to seal his victory before being embraced by his father Gerry.

Yang bogeyed the last to fall back into a tie for third with American pair Kevin Chappel and Robert Garrigus and England's Lee Westwood on six-under.

Woods, who missed the tournament through injury and has not won a major since the 2008 U.S. Open, sent his congratulations.

"Heck of a performance," Woods said in a statement. "Congrats and well done. Enjoy it. This was an impressive performance."